Okay, I understand now. The report generation in TestStand has nothing to do with LabVIEW. The reports are generated in either reportgen_html.seq or reportgen_txt.seq. Do you want to append the serial number and date at the very end of the report or with each step result?
p.s. There is a discussion forum just for TestStand that you would be better off posting to especially since your question does not involve LabVIEW. Go
here and click the TestStand link.